Scaling of MOS transistors, which has been a driving force for the semiconductor industry for more than 40 years, is now becoming more and more difficult to execute. One possible solution for continuing the trend of performance increase of MOS transistors is to replace the silicon channel by other semiconductors, such as Ge or III-V. However, although having superior transport properties compared to Si, III-V materials based devices seem to have more severe short channel effects and leakage currents than in the case of silicon technology. It is therefore necessary to rigorously evaluate the intrinsic performance of these devices. This work presents a theoretical evaluation of the performance of MOSFET devices based on III-V materials and demonstrates that higher dielectric constants and lower effective masses of these materials will lead to larger and more damaging phenomena than in the case of silicon based devices.